West Nile virus remains the foremost mosquito-borne illness in the continental United States, with a surge in reported cases raising public health concerns. As of late September 2025, the U.S. Centers for Disease Control and Prevention (CDC) has recorded over 1,100 human infections spanning 42 states. These cases include nearly 750 instances of the neuroinvasive form, a severe manifestation in which the virus infects the central nervous system, potentially leading to long-term neurological damage or death. This escalation represents a roughly 40% increase over typical annual figures, indicating a troubling trend for mosquito-borne diseases in the region.
Recent epidemiological trends suggest that climate change may be a key driver in prolonging and intensifying the mosquito season, traditionally ending in October in the U.S. Warmer temperatures create favorable breeding conditions and extend the period during which mosquitoes are active and capable of transmitting viruses. Colorado, for instance, has reported a staggering 220 cases this year, the highest among any single state, highlighting regional vulnerabilities amplified by environmental factors.
West Nile virus is primarily transmitted through the bite of infected mosquitoes, specifically those capable of carrying the virus from birds—its natural reservoir—to humans. The virus is not spread through direct human-to-human contact, such as respiratory droplets or casual interaction. While a majority of infected individuals remain asymptomatic, a portion develop flu-like symptoms, and a subset of these cases progress to severe neuroinvasive disease, necessitating hospitalization.
Despite this rising threat, public concern appears remarkably muted. A nationally representative survey conducted by the Annenberg Public Policy Center in August 2025 reveals that only 15% of U.S. adults express worry about contracting West Nile virus or dengue fever, a related mosquito-borne illness. This level of apprehension has remained stable since the previous year, suggesting a disconnect between the rising incidence and public awareness or concern.
The survey also uncovers substantial gaps in knowledge about the transmission and symptoms of these illnesses. While three-quarters of respondents understand mosquitoes are the vectors, nearly half remain uncertain about the symptoms associated with West Nile virus infection. Common symptoms such as fever, muscle and joint pain, headache, and nausea are recognized only by a portion of the population, whereas some individuals erroneously associate unrelated symptoms with the disease.
Concerning treatment, public understanding is limited. No antiviral therapy currently exists for West Nile virus or dengue fever, yet only 22% of survey participants are aware of this fact. The majority either harbor uncertainty or mistakenly believe antiviral treatments are available, underscoring a critical area for public health education.
Preventive behaviors show a moderate uptake among the population. About 61% of adults report taking routine measures to avoid mosquito bites year-round. Among those who take precautions, actions such as eliminating standing water to disrupt breeding sites, avoiding exposure during peak mosquito activity, and using insect repellents are common. However, other methods like repairing window screens or wearing protective clothing are less consistently practiced, and the use of mosquito netting remains rare.
Knowledge about the proper use of insect repellents—the frontline defense against mosquito bites—is notably deficient. The CDC advises applying repellent only on exposed skin and directly recommends applying sunscreen first, allowing it to absorb before applying repellent. Strikingly, only 14% of individuals correctly understand that repellent should never be applied under clothing, and merely 33% know the correct order of sunscreen and repellent application. Such misinformation could diminish the efficacy of these preventive measures and exacerbate exposure risk.
Furthermore, guidance on selecting effective and safe repellents is not widely comprehended. The CDC endorses EPA-registered repellents containing 20 to 50% DEET concentration, emphasizing that concentrations above this range do not confer additional protection. However, just 19% of respondents recognize the importance of EPA registration, and a substantial segment mistakenly believes the CDC recommends repellents with over 50% DEET. Additionally, there exists confusion around the use of natural repellents, which the CDC does not advise, though some respondents believe otherwise.
Infants under two months old are a sensitive demographic concerning insect repellent use. The CDC explicitly advises against applying repellents to this age group, and while a slim majority are aware of this guidance, nearly half remain unsure, indicating a potential risk for inadvertent exposure.
These findings emerge from the 25th wave of the Annenberg Science and Public Health (ASAPH) survey, which canvassed 1,699 adults nationwide in early August 2025. This longitudinal survey panel allows for ongoing assessment of public knowledge, beliefs, and behaviors on critical health matters. With a margin of error of ±3.5 percentage points and a rigorous sampling design, the data provide reliable insights into the public’s current state of awareness regarding mosquito-borne diseases.
The increasing prevalence of West Nile virus, compounded by extended mosquito seasons driven by climatic changes, underscores the urgency of enhancing public education and intervention strategies. Clear communication about transmission pathways, symptom recognition, the absence of antiviral treatments, and effective preventive practices is imperative. Bridging these knowledge gaps can empower individuals to adopt protective behaviors and mitigate the impact of these escalating vector-borne threats.
As health agencies and researchers confront these evolving challenges, surveys like the ASAPH provide essential feedback on the effectiveness of public messaging and highlight areas demanding intensified outreach. The steady, relatively low level of public concern amidst rising case numbers signals a need to recalibrate communication efforts to resonate more effectively with the populace.
In conclusion, the landscape of mosquito-borne illnesses such as West Nile virus and dengue fever is shifting considerably, influenced by environmental and social factors. While scientific knowledge about the viruses and their prevention is robust, translating this knowledge into public awareness and action remains a critical obstacle. Future efforts must prioritize educating communities, fostering behavioral changes, and maintaining vigilance as mosquito seasons lengthen and threats expand across the United States.
Subject of Research: People
Article Title: Growing West Nile Virus Cases Highlight Urgent Need for Public Awareness and Prevention
News Publication Date: Late September 2025
Web References:
– CDC West Nile Virus Information: https://www.cdc.gov/west-nile-virus/about/index.html
– Current Year Data on West Nile Virus: https://www.cdc.gov/west-nile-virus/data-maps/current-year-data.html
– CDC Mosquito Prevention Guidelines: https://www.cdc.gov/mosquitoes/prevention/index.html
– Annenberg Public Policy Center Survey Topline: https://www.annenbergpublicpolicycenter.org/wp-content/uploads/APPC_ASAPH_mosquitoes_topline-a.pdf
– Annenberg Science and Public Health Survey: https://www.annenbergpublicpolicycenter.org/science-communication/ask/
References: Provided as hyperlinks within the text above.
Image Credits: Annenberg Public Policy Center
Keywords: Mosquitos, Disease prevention, Risk factors, Tropical diseases, Dengue fever, Public health, Public policy, Fever, Headaches, West Nile virus
